In a $\Delta ABC$, $\tan \frac{A}{2} = \frac{5}{6}, \; \tan \frac{C}{2} = \frac{2}{5}$, then :

Question

( A ) $a, \; c, \; b$ are in AP
( B ) $b, \; a, \; c$ are in AP
( C ) $a, \; b, \; c$ are in AP
( D ) $a, \; c, \; b$ are in GP